Acta Crystallographica Section E

Structure Reports Online

Volume 63, Part 7 (July 2007)

inorganic compounds

Acta Cryst. (2007). E63, i164-i165 [ doi:10.1107/S1600536807029790 ]

Redetermination of the Tutton's salt Cs₂[Cu(H₂O)₆](SO₄)₂

P. Ballirano, G. Belardi and F. Bosi

Abstract: The crystal structure of dicaesium hexaaquacopper(II) bis[sulfate(VI)], Cs₂[Cu(H₂O)₆](SO₄)₂, has been redetermined from single-crystal X-ray diffraction data. In comparison with the previous refinement based on single-crystal neutron data [Shields & Kennard (1972). Cryst. Struct. Commun. 1, 189-191], the results show an improved precision and benefit from inclusion of anisotropic displacement parameters for the non-H atoms. The structure is characterized by a mean Cu-O bond length of 2.094 Å. The [Cu(H₂O)₆] octahedron ( $\overline{1}$ symmetry) is strongly distorted because of the Jahn-Teller effect, with a calculated distortion parameter [Delta] of 0.0054. The Cs⁺ cation is ninefold coordinated by seven O atoms and two water molecules, with a mean Cs-O bond length of 3.238 Å.